Water stop



July 9, 1957 LEROY F. HARzA 2,798,373

WATER STOP Filed Feb. 17, 195s y Y Zin/ 4M Arry United States Patent WATER STOP Leroy F. Harza, Chicago, lll.; Fred H. Camphausen and Edward W. Hillier, executors of said Leroy F. Harza, deceased, assignors of fifty percent to Zelma D. Harza, twenty-live percent to Arthur C. Hoffman, and twentytive percent to Richard D. Harza Application February 17, 1953, serial No. 331,365

3 Claims. (Cl. 72-106) This invention relates in general to a water stop for concrete joints and is more particularly described as an interlocking dovetailed joint seal in which the projection of one pour of a concrete joint extends directly between and interlocks with the opposite projections of another pour of the plastic joint with a plastic or rubber type of seal having opposite lobes or projections closely linked between the projections and adapted to be thus inc'orpo'ratedin joints of all types of hydraulic structures which are subject to water pressure such as dams, water receptacles and reservoirs, foundation walls, concrete floors, tunnel linings, and in fact, wherever there may be a leakage path between two opposite sides in which the water stop is incorporated.

In previous types of water stops, it has been proposed that all of the projections from one pour be ylocated on one side of a center line and all of the projections of the other pour be located on the other side of a center line and that the water stop shall have a central web or webs separating the two projections.

In the present invention, the water stop has opposite dovetailed lobes in a relatively thin web but with outer web portions connected by thicker transverse walls. The lobes may have a greater length transversely than their width as they project oppositely which will give them greater strength in the pours to which they are attached. There will also be a greater resistance to a shearing action between the projections of opposite pours and the pulling action or a shrinking movement of the plastic will also cause a tightening of the material of the water stop between adjacent but oppositely extending lobes so that the joint between the pours is more likely to be maintained without breakage of the projections. Limited pulling or separating action between the projections of the pours tends to tighten the material of the water stop between the adjacent but opposite faces of the interlocking projections.

In the present invention, a relatively thin water stop of rubber, rubbery sheet material or plastic may be imbedded at the end of one pour producing recesses and projections in adjacent but opposite lobes, so that a projection of the first pour will be between similarly shaped recesses formed in that pour, the recesses being open at the end of the first pour when the forms are removed. When the second pour is applied thereto, the projections into the recesses of the water stop will be located at opposite sides to cause interengagement with the rst formed projections with relatively thin sections of the water stop between the opposite projections. This produces dovetailed projections at each side of the water stop but adapted to oppose and engage each other in any pulling movement between the pours of the structure to which the water stop is applied and thus providing an interengaging and strengthening construction which does not shear the projections of opposite pours if there is a tendency to a relative movement apart because the opposite projections are actually strengthened by contact and interengagement with each other and the water stop itself is 2,798,373 Patented July 9, 1957 ICC 2. made tighter at the sides of the lobes between the dovetailed projections and they greatly oppose any liquid passage through the joint if there is a tendency to separation of the joint faces or the tendency of a pulling movement between the joint faces.

An important object of the invention is therefore to provide a resilient oppositely dovetailed water stop adapted to be placed in the pour of one form at a joint and to interengage with the material of a second pour at the joint and to make a directly opposed dovetailed connection betweenthe projections of the pours with the material of the water stop between the opposite dovetailed projections.

A further object of the invention is to provide a water stop in the form of opposite hollow angularly dovetailed ribs, the opposite sides of eachof the ribs of the water stop having thickened walls directly engaging the opposed sides of dovetailed projections of the two pours formed by the water stop itself, so that either the cornpression or lseparation of one pour with respect to the other will compress the material of the water stop and will correspondingly tighten or close the water stop against the passage of liquid therethrough.

A further object ofthe invention is to provide a water stop having opposite dovetailed lobes of llexible material l with outer resilient webs connected by transverse thicker wall portions.

Other objects of the invention will appear in the speciiication and will be vapparent from the accompanying drawings in which,

'i l Fig. l is a perspective view of a portion of a water stop in accordance with Vthis invention which may be extruded orforme'd Vin a longitudinal strip of great length.

Fig. 2 is a sectional view of a water seal as shown in Fig. 1 as applied to the first pour of a concrete form at the joint of a wall;

Fig. 3 is a sectional view of a joint completed by the addition of a second pour to that shown in Fig. 2 and incorporating the water seal directly therein; and

Fig. 4 is a sectional view showing how the water stop is tightened between opposite concrete projections in a shrinking or separating action.

This water stop may be made of rubber and other flexible and resilient plastics similar to rubber. It is found preferable to produce it in a continuous extruded form and may be made of a vinyl plastic which has a longer life than rubber. When made of this material, it is practically permanent whereas rubber hardens and becomes brittle in a very short time. This material is immune to attacks by alkalis and concrete is normally alkaline. Water stops made of this material are immune to attack from acids of the type and concentration normally found around dam projects.

Referring now more particularly to the drawings, a continued strip of rubber or other flexible resilient plastic material may be extruded or otherwise formed in a continuous length to provide opposite lobes 10 of dovetailed plastic form having outer webs 12 of relatively thin material connected by thicker transverse walls 14 so that the thin outer webs will spread or expand under tension and the thick walls 14 will oppose compression on opposite sides thereof.

As shown in Fig. 2, a water stop of this kind is attached to an end board 16 of a first pouring form by doubleheaded fastening nails 18 inserted through anges 20 at the sides of the water stop. A dovetailed projection 26 (or projections) of a rst pour 28 is thus formed at one side of the water stop and after a second pour 30 as shown in Fig. 3 opposite dovetailed projections 32 are formed at the sides of the dovetailed projections 26 of the first pour separated by the thin outer webs 12 and thicker connect ing side walls 14 of the water stop, which are thus interposed between the side edges of the adjacent dovetailed Y thin web 12 being of resilient material will tend to buckle V under strain between the pour sections and for a pulling movement, the thick Wall portions 14 will tend to oppose 'such action but will make a tighter water joint on both 'sides of each projection. Likewise, if there is a separating action caused by shrinkage or movement apart of the pours, the thick wall portions will be compressed between the opposite sides of the projections thereby more tightly engaging the water seal' and preventing relative move- Ament of Water at the joint.

This water seal is relatively simple in construction 4and application and has the advantage that an improved water seal is actually provided when the joint between the poured sections tends to open. While a preferred form of the invention has been described in some detail, it should be regarded as an illus- Itration or example of the invention rather than a restricvtion or limitation of the invention since various changes may be made in the construction, combination and arrangement of the parts without'departing from the spirit and scope of the invention.

I claim:

1. A substantially water tight structure of. masonry material comprising a pair of adjacent masses `of such material presenting a broad liquid confining working face and having a joint between said masses substantially perpendicular to said face, and an integral Water seal ,of4 compressible ilexible resilient material sealing said joint, said water seal comprising a plurality of alternately facing convolutions dovetailed in cross section, said convolu tions having longitudinal axes arranged substantially parallel to said working face and successive convolutions being spaced progressively farther from said working face and providing a tortuous seepage path, each said convolution having a minimum `dimension perpendicular to said working face in the direction in which said convolution opens and said masonry masses having rib-like projections thereon fitting in and complementary in shape to said convolutions ,and interlocking with one another, said water seal being tightened and compressed by wedging between such projections upon pulling apart of said masses.

2. A substantially water tight structure as set forth in claim 1 'wherein' the side ilanges of each dovetail are thicker than thev connecting outer web whereby to allow close spacing of said masonry masses and substantial compression of said side flanges lfor greater separation of said masses.

3. A substantially water tight structure as set forth in claim l wherein the water seal terminates short of said working face.

'References Cited in the lfile of this patent UNITED STATES PATENTS 842,068 Bovee Ian. 22, 1907 873,739 Edmondson a Dec. 17, 1907 2,139,851 Roberts Dec. 13, 1938 2,140,226 Harrap Dec. 13, 1938 2,228,052 Gardner Ian. 7, 1941 2,573,482 Peik Oct. 30, 1950 OTHER REFERENCES 

